我正在尝试使用MAX()OVER PARTITION BY函数来评估我公司购买的特定零件的最新收据。以下是去年几个部分的信息示例表:
| VEND_NUM | VEND_NAME | RECEIPT_NUM | RECEIPT_ITEM | RECEIPT_DATE |
|----------|--------------|-------------|----------|--------------|
| 100 | SmallTech | 2001 | 5844HAJ | 11/22/2017 |
| 100 | SmallTech | 3188 | 5521LRO | 12/31/2017 |
| 200 | RealSolution | 5109 | 8715JUI | 05/01/2017 |
| 100 | SmallTech | 3232 | 8715JUI | 11/01/2017 |
| 200 | RealSolution | 2101 | 4715TEN | 01/01/2017 |
如您所见,第三和第四行显示了SAME部件号的两个不同供应商。
这是我当前的查询:
WITH
-- various other subqueries above...
AllData AS
(
SELECT VEND_NUM, VEND_NAME, RECEIPT_NUM, RECEIPT_ITEM, RECEIPT_DATE
FROM tblVend
INNER JOIN tblReceipt ON VEND_NUM = RECEIPT_VEND_NUM
WHERE
VEND_NUM = '100' OR VEND_NUM = '200' AND RECEIPT_DATE >= '01-Jan-2017'
),
SELECT MAX(RECEIPT_DATE) OVER PARTITION BY(RECEIPT_ITEM) AS "Recent Date", RECEIPT_ITEM
FROM AllData
我的回归设置如下:
| Recent Date | RECEIPT_ITEM |
|-------------|--------------|
| 11/22/2017 | 5844HAJ |
| 12/31/2017 | 5521LRO |
| 11/01/2017 | 8715JUI |
| 11/01/2017 | 8715JUI |
| 01/01/2017 | 4715TEN |
但是,它应该是这样的:
| Recent Date | RECEIPT_ITEM |
|-------------|--------------|
| 11/22/2017 | 5844HAJ |
| 12/31/2017 | 5521LRO |
| 11/01/2017 | 8715JUI |
| 01/01/2017 | 4715TEN |
有人可以就我做错了什么提出建议吗?看起来它只是简单地取代了最近的日期,而不仅仅是给了我想要的最新日期。
最终,我希望我的桌子看起来像这样。但是,我不知道如何正确使用MAX()或MAX()OVER PARTITION BY()函数来实现这个目的:
| VEND_NUM | VEND_NAME | RECEIPT_NUM | RECEIPT_ITEM | RECEIPT_DATE |
|----------|--------------|-------------|----------|--------------|
| 100 | SmallTech | 2001 | 5844HAJ | 11/22/2017 |
| 100 | SmallTech | 3188 | 5521LRO | 12/31/2017 |
| 100 | SmallTech | 3232 | 8715JUI | 11/01/2017 |
| 200 | RealSolution | 2101 | 4715TEN | 01/01/2017 |
答案 0 :(得分:2)
使用窗口函数ROW_NUMBER() OVER (PARTITION BY receipt_item ORDER BY receipt_date DESC)
为每一行分配序列号。 receipt_date
的最新receipt_item
行将编号为1。
WITH
-- various other subqueries above...
AllData AS
(
SELECT VEND_NUM, VEND_NAME, RECEIPT_NUM, RECEIPT_ITEM, RECEIPT_DATE,
ROW_NUMBER() OVER (PARTITION BY RECEIPT_ITEM ORDER BY RECEIPT_DATE DESC ) AS RN
FROM tblVend
INNER JOIN tblReceipt ON VEND_NUM = RECEIPT_VEND_NUM
WHERE
VEND_NUM IN ( '100','200') AND RECEIPT_DATE >= '01-Jan-2017'
)
SELECT VEND_NUM, VEND_NAME, RECEIPT_NUM, RECEIPT_ITEM, RECEIPT_DATE
FROM AllData WHERE RN = 1
答案 1 :(得分:1)
我在这里看到了几个问题。一,使用聚合函数MAX()
作为分析函数的语法(这是Oracle帮助调用窗口函数的函数)如下所示:
MAX(receipt_date) OVER ( PARTITION BY receipt_item )
(注意括号的位置)。其次,从您想要的结果集中,您实际上并不想要一个窗口函数,而是想要聚合。窗口(或分析)函数将始终为其分区中的每一行返回一行;这就是它的工作方式。所以我认为你想要的是:
WITH
-- various other subqueries above...
AllData AS
(
SELECT VEND_NUM, VEND_NAME, RECEIPT_NUM, RECEIPT_ITEM, RECEIPT_DATE
FROM tblVend
INNER JOIN tblReceipt ON VEND_NUM = RECEIPT_VEND_NUM
WHERE ( VEND_NUM = '100' OR VEND_NUM = '200' ) AND RECEIPT_DATE >= DATE'2017-01-01'
)
SELECT VEND_NUM, VEND_NAME, RECEIPT_NUM, RECEIPT_ITEM, MAX(RECEIPT_DATE)
FROM AllData
GROUP BY VEND_NUM, VEND_NAME, RECEIPT_NUM, RECEIPT_ITEM;
现在我对上面做了一些小改动,例如围绕OR
条件括起括号(使用IN ('100','200')
可能更好),因为AND
优先于OR
(所以你的查询会得到VEND_NUM = '100' OR ( VEND_NUM = '200' RECEIPT_DATE >= DATE'2017-01-01' )
的结果......但也许这就是你想要的?)。
答案 2 :(得分:1)
只是路过,但我认为您必须将日期格式化为“ YYYY-MM-DD”格式,这样才不会考虑“时间”。
答案 3 :(得分:0)
这是对问题的原始版本的回答。
您的where
子句应该如下所示:
WHERE VEND_NUM IN ('100', '200') AND RECEIPT_DATE >= DATE '2017-01-01'
很有可能你想要的只是:
SELECT DISTINCT RECEIPT_DATE, RECEIPT_ITEM
FROM tblVend INNER JOIN
tblReceipt
ON VEND_NUM = RECEIPT_VEND_NUM
WHERE VEND_NUM IN ('100', '200') AND RECEIPT_DATE >= DATE '2017-01-01';
至少,这会返回您想要返回的内容。